Sleep deprivation is common, but that doesn't make it any less dangerous. Find out how a lack of sleep can affect your mind, weight and immune system. By Mayo Clinic Staff

Sleep deprivation is more harmful that you might realize. Understand the possible consequences of sleep deprivation and what you can do about it.

Sleep deprivation occurs when you don't get enough sleep to feel alert and well rested. While the amount of sleep a person needs varies a little, most adults need about seven to eight hours of sleep every night.

Sleep deprivation can occur if you don't get enough total hours of sleep or as a result of poor quality sleep. Common causes of sleep deprivation include work hours, medical conditions, stress and personal obligations, such as caring for a baby or a sick loved one.

Sleep deprivation causes excessive daytime sleepiness. The consequences of sleep deprivation can include:

  • Changes in cognitive function. Research shows that people who get inadequate sleep over many nights don't perform as well on complex mental tasks as do people who get closer to seven hours of sleep a night. Sleep deprivation can also cause irritability, decreased libido and poor judgment.
  • Weight gain. Sleeping less than five hours a night might increase the likelihood of weight gain. This could be because sleep duration affects hormones regulating hunger and stimulates the appetite. Sleep deprivation also leads to fatigue, which can result in less physical activity.
  • High blood pressure. Sleeping five hours or less a night might increase the risk of developing high blood pressure or worsening already high blood pressure.
  • Weakened immune system. Studies show that people who don't get quality sleep or enough sleep are more likely to get sick after being exposed to a virus, such as the common cold. Lack of sleep can also affect how fast you recover if you do get sick.
  • Crashes. Excessive sleepiness is a major cause of car and truck crashes.
  • Quality of life. Sleep deprivation might cause you to cut back on enjoyable activities due to fatigue. Inappropriate drowsiness or unplanned naps might also cause friction at home and at work.

A recent study also reported that men who slept less than six hours a night had a higher overall risk of premature death than men who slept six hours or more a night.

The best way to overcome the fatigue caused by sleep deprivation is to meet your sleep needs — by either increasing the amount of time you sleep or improving your sleep quality. If possible, sleep in until you wake up on your own feeling alert for several days in a row. Strategic short naps — less than 30 minutes — also can help. If you know you're about to experience sleep loss, getting extra sleep beforehand might reduce the impact on your alertness and performance.

If sleeping in or napping isn't possible, physical activity, caffeine, bright light exposure or prescription medications might temporarily help you deal with sleep deprivation. Keep in mind, however, that there's no substitute for getting enough quality sleep.

Sep. 28, 2013